What is meant by the "Accuracy limit factor ALF" for a protective current transformer?

According to IEC 61869-2, the accuracy limit factor (ALF) is the ratio of the rated accuracy limit primary current (value of primary current up to which the current transformer complies with the requirements for composite error) to the rated primary current.
Standard values are: 5, 10, 15, 20 or 30.

Released for: Schneider Electric Canada